Poly(ethylene-co-1-octene) characterization by high-temperature multidimensional NMR at 750 MHz

Herein are presented the 188.6 MHz C-13 NMR spectra (corresponding to 750 M Hz H-1 resonance frequency) of a series of copolymers from ethylene and 1-o ctene monomers. These spectra permit the resolution of unique C-13 resonanc es from hexyl chain branches. The 750 MHz high-temperature pulsed field gra dient (PFG), heteronuclear multiple quantum correlation (HMQC), and heteron uclear multiple-bond correlation (HMBC) two-dimensional (2D) NMR spectra of ethylene/1-octene copolymers are also presented. Data are presented from a new probe capable of performing high-temperature PFG coherence selection e xperiments at temperatures typical of those used in many polymer analyses. The performance of this probe is illustrated with PFG-HMQC and PFG-HMBC spe ctra of copolymers from ethylene/1-octene at 120 degreesC. Detailed unequiv ocal proof of the resonance assignments for poly(ethylene-co-1-octene) is r eported. The 2D NMR spectra were used to confirm H-1 and C-13 chemical shif t assignments previously determined by empirical methods. Quantitative anal yses of the ethylene/1-octene copolymers were also performed.